diff options
Diffstat (limited to 'libtommath/bn_mp_invmod.c')
-rw-r--r-- | libtommath/bn_mp_invmod.c | 50 |
1 files changed, 15 insertions, 35 deletions
diff --git a/libtommath/bn_mp_invmod.c b/libtommath/bn_mp_invmod.c index 36011d0..7b35a24 100644 --- a/libtommath/bn_mp_invmod.c +++ b/libtommath/bn_mp_invmod.c @@ -1,43 +1,23 @@ -#include <tommath_private.h> +#include "tommath_private.h" #ifdef BN_MP_INVMOD_C -/* LibTomMath, multiple-precision integer library -- Tom St Denis - * - * LibTomMath is a library that provides multiple-precision - * integer arithmetic as well as number theoretic functionality. - * - * The library was designed directly after the MPI library by - * Michael Fromberger but has been written from scratch with - * additional optimizations in place. - * - * The library is free for all purposes without any express - * guarantee it works. - * - * Tom St Denis, tstdenis82@gmail.com, http://libtom.org - */ +/* LibTomMath, multiple-precision integer library -- Tom St Denis */ +/* SPDX-License-Identifier: Unlicense */ /* hac 14.61, pp608 */ -int mp_invmod (mp_int * a, mp_int * b, mp_int * c) +mp_err mp_invmod(const mp_int *a, const mp_int *b, mp_int *c) { - /* b cannot be negative */ - if ((b->sign == MP_NEG) || (mp_iszero(b) == MP_YES)) { - return MP_VAL; - } + /* b cannot be negative and has to be >1 */ + if ((b->sign == MP_NEG) || (mp_cmp_d(b, 1uL) != MP_GT)) { + return MP_VAL; + } -#ifdef BN_FAST_MP_INVMOD_C - /* if the modulus is odd we can use a faster routine instead */ - if ((mp_isodd(b) == MP_YES) && (mp_cmp_d(b, 1) != MP_EQ)) { - return fast_mp_invmod (a, b, c); - } -#endif + /* if the modulus is odd we can use a faster routine instead */ + if (MP_HAS(S_MP_INVMOD_FAST) && MP_IS_ODD(b)) { + return s_mp_invmod_fast(a, b, c); + } -#ifdef BN_MP_INVMOD_SLOW_C - return mp_invmod_slow(a, b, c); -#else - return MP_VAL; -#endif + return MP_HAS(S_MP_INVMOD_SLOW) + ? s_mp_invmod_slow(a, b, c) + : MP_VAL; } #endif - -/* ref: $Format:%D$ */ -/* git commit: $Format:%H$ */ -/* commit time: $Format:%ai$ */ |